The present invention relates to removable braces for supporting a user's limb at a joint thereof, such as the knee joint of a leg, and specifically to rigid and semi-rigid support braces.
Knee braces and the like are well known in the art for controlling and stabilizing a joint area in the event of an injury or other instability of the limb or the joint. Injuries to a joint area such as the straining or tearing of ligaments, tendons or cartilage occur when a limb becomes twisted, hyperextended or otherwise contorted into unnatural positions. These kinds of injuries are often the result of participation in athletic contests such as football and basketball, but they occur in a variety of ways. Of current interest are devices which can be worn by those who have sustained various knee injuries and which will both protect the knee against further injury, and support the injured or weakened knee sufficiently to allow one to resume activities on the playing field, in the work place, and so forth.
The prior art includes removable rigid support braces worn about the knee area. Such braces typically comprise a rigid sheath member approximately two feet long which conforms generally to the shape of a leg above and below the knee for placement about the knee area. The sheath member usually includes padding such as foam rubber on the inside to size the sheath to the leg and enable a somewhat comfortable fit. Such rigid sheaths are strong enough to resist sudden twisting, bending and so forth and thereby prevent hyperextension and other injurious lateral, fore and aft movement of the knee. Flexible braces have much less structural strength than rigid braces and are thus less effective in preventing hyperextension or other injurious knee movement.
The rigid brace currently available, however, are characterized by various disadvantages. The padding in rigid braces has only a limited capacity for sizing the sheath to the leg because the quantity of such padding is not continuously adjustable. If a user desires additional padding to improve the comfort or fit of the brace, none of the options presently available are very adequate. For example, a user may simply place additional padding, cloth or whatever soft material is readily available, between the brace and the leg. Such additional padding may thereafter fall out or shift about undesirably. It is also difficult to achieve a consistent fit from one use to the next in this manner. Further, rigid braces are unable to provide selectively adjustable stabilizing pressure to the knee, or different pressure to different points on the knee, which would be helpful in correcting knee instabilities and in achieving proper alignment of the knee during healing thereof.
The prior art includes various flexible knee braces which solve some of these problems, but introduce others. These braces typically include a flexible sleeve or sheath made of a suitable flexible fabric or elastic material and are thus much more comfortable and form-fitting than the rigid braces. The flexible fabric or elastic material from which they are made more ably adjusts and conforms to the contours of the limb than the padding in a rigid brace which is restrained by the rigid sheath.
However, although flexible knee braces more ably conform to leg size, they fail to provide the same degree of protection against hyperextension and other abnormal knee movement offered by rigid braces, because a flexible sheath or sleeve has much less strength than a rigid or semi-rigid sheath as discussed above. U.S. Pat. Nos. 3,786,804 and 4,938,207 attempt a solution to this problem by teaching a pair of flat vertical support arms, one such arm mounted upon each side of a flexible brace to provide some rigidity to the brace and to thereby protect against abnormal knee movement. However, although this approach does provide some protection against abnormal lateral movement, such protection is vastly inferior to that offered by a rigid or semi-rigid support brace which provides far more rigid structure than the support arms.
Users have thus had to choose between the comfort and adjustable fit offered by the flexible braces, and the superior protection against hyperextension and other abnormal lateral, fore and aft movement offered by the rigid braces.
Although the industry continues to research and develop devices for controlling instabilities in the knee and other joints, none of the braces known to applicant can single-handedly solve the problems discussed above. It is clear that there is a need for a joint-supporting brace which not only provides superior protection against hyperextension and other abnormal joint movement, but which can also customize a secure and comfortable fit to the limb, and which can be adjusted with respect to various leg sizes and contours.